BI-1607 in Combination with Trastuzumab in Subjects with HER2-positive Advanced Solid Tumors

Main Inclusion Criteria:

* Is willing and able to provide written informed consent for the trial.
* Is ≥18 years of age on day of signing informed consent.
* Has received standard of care or is intolerant to standard of care antineoplastic therapy. Subjects who are intolerant to trastuzumab cannot be enrolled in the study.
* Has at least 1 measurable disease lesion as defined by RECIST v1.1 criteria.
* Has a locally confirmed HER2+ tumor.
* Must have progressive disease after the last line of treatment. In addition, subjects must have received the following previous lines of treatment:

  1. Prior lines of treatment including trastuzumab and chemotherapy.
  2. At least one prior line of treatment with an antibody-drug conjugate (ADC) (eg, trastuzumab-emtansine \[TDM-1, or trastuzumab-deruxtecan\]).

Main Exclusion Criteria:

* Needs doses of prednisolone \>10 mg daily (or equipotent doses of other corticosteroids) while on the trial other than as premedication.
* Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
* Has cardiac or renal amyloid light-chain amyloidosis.
* Has had clinically significant lung disease requiring systemic corticosteroid treatment within the last 6 months of enrollment.
* Has an active, known, or suspected autoimmune disease.
* Is at high medical risk because of nonmalignant systemic disease including severe active infections on treatment with antibiotics, antifungals, or antivirals.
* Has presence of chronic graft versus host disease.
* Has had an allogenic tissue/solid organ transplant.
* Has uncontrolled or significant cardiovascular disease.
* Has a known additional malignancy of another type, except for adequately treated cone-biopsied carcinoma in situ (eg, breast carcinoma, cervical cancer in situ), adequately controlled superficial bladder cancer, and basal or squamous cell carcinoma of the skin.
* Has a diagnosis of primary or acquired immunodeficiency disorder or is taking any other form of immunosuppressive therapy.